Hello,
The new documentation has not been updated with it yet, but there is an R script on the old documentation page of the MouseTracker element. The first four numbers (preceded by w, h, x and y) report the width and height of the page, and the x/y coordinates of the mouse when the MouseTracker element’s start command is executed. After that, the string is a series of triplets of numbers, each triplet is prefixed with t and the numbers are separated by +/-: the first number is the number of milliseconds that have elapsed since the previous triplet (t is for “time”), the second number is how many pixels the mouse moved horizontally (+ = right, - = left) and the third number is how many pixels the mouse moved vertically (+ = down, - = up)
Jeremy